Hi,
Two minor issues.
On 6/9/22 14:29, Sughosh Ganu wrote:
Add documentattion for the FWU Multi Bank Update feature. The document
s/documentattio/documentation
describes the steps needed for setting up the platform for the feature, as well as steps for enabling the feature on the platform.
Signed-off-by: Sughosh Ganu sughosh.ganu@linaro.org
doc/develop/uefi/fwu_updates.rst | 142 +++++++++++++++++++++++++++++++ doc/develop/uefi/index.rst | 1 + doc/develop/uefi/uefi.rst | 2 + 3 files changed, 145 insertions(+) create mode 100644 doc/develop/uefi/fwu_updates.rst
diff --git a/doc/develop/uefi/fwu_updates.rst b/doc/develop/uefi/fwu_updates.rst new file mode 100644 index 0000000000..1c34beb7d5 --- /dev/null +++ b/doc/develop/uefi/fwu_updates.rst @@ -0,0 +1,142 @@ +.. SPDX-License-Identifier: GPL-2.0+ +.. Copyright (c) 2022 Linaro Limited
+FWU Multi Bank Updates in U-Boot +================================
+The FWU Multi Bank Update feature implements the firmware update +mechanism described in the PSA Firmware Update for A-profile Arm +Architecture specification[1]. Certain aspects of the Dependable +Boot specification[2] are also implemented. The feature provides a +mechanism to have multiple banks of updatable firmware images and for +updating the firmware images on the non-booted bank. On a successful +update, the platform boots from the updated bank on subsequent +boot. The UEFI capsule-on-disk update feature is used for performing +the actual updates of the updatable firmware images.
+The bookkeeping of the updatable images is done through a structure +called metadata. Currently, the FWU metadata supports identification +of images based on image GUIDs stored on a GPT partitioned storage +media. There are plans to extend the metadata structure for non GPT +partitioned devices as well.
+Accessing the FWU metadata is done through generic API's which are +defined in a driver which complies with the u-boot's driver model. A +new uclass UCLASS_FWU_MDATA has been added for accessing the FWU +metadata. Individual drivers can be added based on the type of storage +media, and it's partitioning method. Details of the storage device +containing the FWU metadata partitions are specified through a U-Boot +specific device tree property `fwu-mdata-store`. Please refer to +U-Boot `doc <doc/device-tree-bindings/firmware/fwu-mdata.txt>`__ for +the device tree bindings.
+Enabling the FWU Multi Bank Update feature +------------------------------------------
+The feature can be enabled by specifying the following configs::
- CONFIG_EFI_CAPSULE_ON_DISK=y
- CONFIG_EFI_CAPSULE_FIRMWARE_MANAGEMENT=y
- CONFIG_EFI_CAPSULE_FIRMWARE=y
- CONFIG_EFI_CAPSULE_FIRMWARE_RAW=y
- CONFIG_FWU_MULTI_BANK_UPDATE=y
- CONFIG_CMD_FWU_METADATA=y
- CONFIG_DM_FWU_MDATA=y
- CONFIG_FWU_MDATA_GPT_BLK=y
- CONFIG_FWU_NUM_BANKS=<val>
- CONFIG_FWU_NUM_IMAGES_PER_BANK=<val>
+in the .config file
+The first group of configs enable the UEFI capsule-on-disk update +functionality. The second group of configs enable the FWU Multi Bank +Update functionality. Please refer to the section +:ref:`uefi_capsule_update_ref` for more details on generation of the +UEFI capsule.
+Setting up the device for GPT partitioned storage +-------------------------------------------------
+Before enabling the functionality in U-Boot, certain changes are +required to be done on the storage device. Assuming a GPT partitioned +storage device, the storage media needs to be partitioned with the +correct number of partitions, given the number of banks and number of +images per bank that the platform is going to support. Each updatable +firmware image will be stored on an separate partition. In addition, +the two copies of the FWU metadata will be stored on two separate +partitions.
+As an example, a platform supporting two banks with each bank +containing three images would need to have 2 * 3 = 6 parititions plus
s/parititions/partitions/
+the two metadata partitions, or 8 partitions. In addition the storage +media can have additional partitions of non-updatable images, like the +EFI System Partition(ESP), a partition for the root file system etc.
+When generating the partitions, a few aspects need to be taken care +of. Each GPT partition entry in the GPT header has two GUIDs::
- *PartitionTypeGUID*
- *UniquePartitionGUID*
+The PartitionTypeGUID value should correspond to the *image_type_uuid* +field of the FWU metadata. This field is used to identify a given type +of updatable firmware image, e.g. u-boot, op-tee, FIP etc. This GUID +should also be used for specifying the `--guid` parameter when +generating the capsule.
+The UniquePartitionGUID value should correspond to the *image_uuid* +field in the FWU metadata. This GUID is used to identify images of a +given image type in different banks.
+Similarly, the FWU specifications defines the GUID value to be used +for the metadata partitions. This would be the PartitionTypeGUID for +the metadata partitions.
+When generating the metadata, the *image_type_uuid* and the +*image_uuid* values should match the *PartitionTypeGUID* and the +*UniquePartitionGUID* values respectively.
+Performing the Update +---------------------
+Once the storage media has been partitioned and populated with the +metadata partitions, the UEFI capsule-on-disk update functionality can +be used for performing the update. Refer to the section +:ref:`uefi_capsule_update_ref` for details on how the update can be +invoked.
+On a successful update, the FWU metadata gets updated to reflect the +bank from which the platform would be booting on subsequent boot.
+Based on the value of bit15 of the Flags member of the capsule header, +the updated images would either be accepted by the u-boot's UEFI +implementation, or by the Operating System. If the Operating System is +accepting the firmware images, it does so by generating an empty +*accept* capsule. The Operating System can also reject the updated +firmware by generating a *revert* capsule. The empty capsule can be +applied by using the exact same procedure used for performing the +capsule-on-disk update.
+Generating an empty capsule +---------------------------
+The empty capsule can be generated using the mkeficapsule utility. To +build the tool, enable::
- CONFIG_TOOLS_MKEFICAPSULE=y
+Run the following commands to generate the accept/revert capsules::
+.. code-block:: bash
- $ ./tools/mkeficapsule \
[--fw-accept --guid <image guid>] | \[--fw-revert] \<capsule_file_name>+Links +-----
+* [1] https://developer.arm.com/documentation/den0118/a/ - FWU Specification +* [2] https://git.codelinaro.org/linaro/dependable-boot/mbfw/uploads/6f7ddfe3be24e... - Dependable Boot Specification diff --git a/doc/develop/uefi/index.rst b/doc/develop/uefi/index.rst index 7e65dbc5d5..e26b1fbe05 100644 --- a/doc/develop/uefi/index.rst +++ b/doc/develop/uefi/index.rst @@ -13,3 +13,4 @@ can be run an UEFI payload. uefi.rst u-boot_on_efi.rst iscsi.rst
- fwu_updates.rst
diff --git a/doc/develop/uefi/uefi.rst b/doc/develop/uefi/uefi.rst index 941e427093..536b278dd9 100644 --- a/doc/develop/uefi/uefi.rst +++ b/doc/develop/uefi/uefi.rst @@ -277,6 +277,8 @@ Enable ``CONFIG_OPTEE``, ``CONFIG_CMD_OPTEE_RPMB`` and ``CONFIG_EFI_MM_COMM_TEE`
[1] https://optee.readthedocs.io/en/latest/building/efi_vars/stmm.html
+.. _uefi_capsule_update_ref:
- Enabling UEFI Capsule Update feature
Regards
Patrick